Buttonhole-stitching machine



C. E. CASGHAIN.

BUTTONHOLE STITCHING MACHINE.

APPLICATION man MAR. 23. 1921.

'f Patented-Apr. 4, 1922.

PATENT OFFICE.

CHARLES E. CASGRAIN, OF CHICAGO, ILLINOIS.

BUTTONHOLE-STITCHING MACHINE.

Application :ned March 23, 1921.

1o all whom t may concern: l

Be it known that I, CIL-xmms E. Casenarn,

a citizen of the United States, and a resident.

20th, 1895, the needle bar has a number of" movements. yIt reciprocates axially, rotates lon its axis, and is given a vibratory or swinging movement. In the construction and arrangement heretofore used, the needle bar at its upper end passes through a spherical bearing member or ball through which it reciprocates, and this ball is held down in a spherical seat by means of a nut engaging against a semi-spherical bushing, the ball working in its bearing socket while the needle bar is vibrated or swung. Vith this construction and arrangement, pressure is directly communicated from the lock nut to the ball member of the bearing and unless the adjustment is at all times kept very accurate the operation will not be efficient. ,As the machine operates very rapidly and the needle bar reciprocates, rotates, and swings all at the same time, it must have freedom of movement without too much play. It in this prior construction too much pressure is applied on the ball member there will be too much friction and'proper operation ot the stitching mechanism will be interfered with. On the other hand, if the adjustment is too loose, the parts will rattle and will not accurately and efficiently operate. In other words, unless the adjustment is kept accurate at all times, accurate co-operation of the various parts is not assured and the needle will not travel accurately and the result has been breaking of the needle and disturbance or breaking of the looping members which co-operate with the needle to form the stitches.

The object of my invention is to provide improved bearing mechanism for the needle bar so that it will more or less automatically be kept in proper'adjustment at all times? Specification of Letters Patent.

Patented Apr. 4, 1922.

Serial No. 454,938.

In accordance with my invention I interpose a spring to iit between an adjustable abut-ment and a bearing head which is semispherical, the interposition of the spring causing the bearing parts to be accurately held together at all times to prevent loose motion and rattling while at the same time the bearing engagement is suiiiciently yielding to prevent interference with the smooth, ib'eady and accurate operation of the needle On the accompanying drawings, I have shown my invention applied to a buttonhole sewing machine, only such parts ot the niachine itself being shown as will serve to illustrate the application of the invention. In the drawings Fig. 1 is a side elevational view of the front end of a sewing machine head showing the needle bar arranged therein together with my improved bea-ring mechanism,

Fig. 2 is an enlarged `vertical sectional viev of the frame and needle bar mechanism, an

F ig. 3 is an enlarged sectional view on y in the front end of the .lever 13 which is pivcted inthe frame 5 at 14 and is connected at its inner end with suitable cam mechanism (not shown) but fully disclosed in Patl ent No. 544,827 dated August 20th, 1895. The lever 13 supports the needle bar and during rocking of, the lever on its pivot the needle bar is vertically reciprocated to bring the needle 15 into co-operative association with the loopers and other stitching mechanism.

Extending upwardly through the bearing enlargement 7 is the cylindrical hollow hub 16 which at its lower end carries the horizontal gear 17 which is engaged by the segmental gear 18 operated by suitable cam mechanism (not shown) to rock at certain times and to certain de Vrees to impart movement to the gear 17. Ille hub and gear 'are rotatably held in place by the collar 19 secured to the sleeve by set screws 2O and resting on top of the enlargement 7. Extending downwardly from the gear 1.7 and concentric therewith is the cylindrical shell 2l closed at its lower end by the detachable plate 22. Reeiprocable transversely through the shell is the block 23 which has the notch 24 providing the wedging or cam surface 25. Within the hub 16 is the sleeve 26 which at During operation ot the lhuttonhole selwing machine the needle bar is rapidly reciprocated vertically, swung laterally and rotated on its axis and the parts shown for accomplishing these movements are disclosed in earlier patents and form no part of my invention. However, to permit such com pleX and numerous movements of the needle bar and to permit the needle to co-operate accurately with the work and' with the its lower end has t-he flange 27 bearing -loopers and other delicate stitch forming deagainst the lower face of the gear 17 and from this flange extends the cam tongue 28 which engages in the groove 24 and has the wedging or cam surface 29 for rio-operating with the cam surface of the block 2?. Compression springs 30 seating on the plate 22 engage against the flange 27 and tend to hold the tongue 28 in its upper position. When the sleeve 26 is shifted downwardly the wedging or cam surfaces 25 and 29 cooperate to shift the block 23 outwardly, thc spring 3l resisting such movement ci the `block and serving to restore it when the sleeve 26 is raised to withdraw the cam tongue 28. The spring 8l. seats in the pocket 32 formed in the block and abuts at its outer end against the yoke frame or brace 38 secured to the frame 21.

The needle bar 8 extends downwardly through the Vsleeve 26 and through the hole 34 provided in the block 23, and the hole 35 provided in the plate 22. Then the block 23 is shifted the needle bar will. be swung and to avoid binding sulicient clearance is provided for the hole 34. As is well understood,.such swing of the needle bar is necesu sary to form the buttonhole stitches. The rock lever 36 extending through the frame 5 and pivoted at 36 straddles the needle bar at its front end and engages with the top of the sleeve 26. By suitable cam mechanism (not shown) the lever is rocked and forces thesleeve 26 downwardly against the force of the spring 30, the spring returning the sleeve to its upper position` While the needle bar is reciprocated vertically and swung laterally, it is also rotated on its axis as the stitches are lrept at right angles with the edgesor line ot' the buttonhole to be stitched. As shown, the needle bar near its lower end has the keyway 37 into which projects the key 38 detachably secured to the block The block being seated in theframe2l and this trame beingr connected with the gear 17, the needle bar is rotated when the gear i7 is turned. The degree and time of turning` ot the gear 17 is controlled byy cam mechanism (not. shown) whlch operates the segmental gear 18 which has already been referred to. To permit klateral swing of the needle bar, sufficient clearance is provided in the sleeve 26 through which the bar extends, this being plainly shownin Fig. 2.

vices, great care must be taken to provide suitable bearing for the needle bar so that the bar will be free to operate smoothly and accurately at all times and also be prevented trom having too much freedom which would cause rattling and uncertain work. My in vention, therefore, resides particularly in the bearing mechanism provided in the upper enlargement 6 through which the needle bar extends. In the enlargement I provide a semi-spherical bearing pocket 39 tor receiving the semispherical bearing head 40 at the lower end of the bearing sleeve 4l which receives the needle bar and in which it may freely turn and reciprocate. In the top of the hearing head 40 is the annular groove 42 for seating the lower end of the compression spring 43. At its. upper end the spring abuts against the cap 44 which by .its flange 45 has threaded engagement in the head 6, the cap being thus adjustable to vary the pressure of the spring against the bearing head 40. The sleeve 4l extends upwardly `through the opening 46 in the cap 44, sufficient clearance space being provided to permit movement of the sleeve as it swings with the needle bar.

When the machine is in operation the needle bar is rapidly reciprocated in the sleeve 4l and at the same time it is rapidl vibrated, and during such vibration whic changes its direction as the needle bar is.

Yturned to keep the stitches at right angles with the buttonhole edge, the bearing :head 40 rapidly vibrates inthe pocket 39. The cap 44 is adjusted to cause the spring 43 to hold the head 40 in bearing engagement with the bearing pocket at all times and to revent the bearing head from jumping o its seat during rapid vibration of the needle bar. However, theadjustment of the spring is not foo tight so that unnecessary friction wouldbe produced. By meansof the spring interposed between the adjusting cap and the-bearing head, adjustment can Abe Vmade which will cause theneedle barto function freely and accurately and noiselessly. In prior construction Vwhere an adjusting cap or bushing engages directly with a'spherical hall bearing member, such accurate, ellicient and noiseless operation is not possible for if `the adjusting bushing is turned the least bit too far in one direction it will clamp the ball too tight and cause unnecessary friction and if turned too far in the other direction, it will permit rattling, either condition resulting in inaccurate and uncertain work. However, by interposing the spring, a little overturning in one direction or the other would not matter as the spring would function to keep the bearing surfaces together with the proper pressure. The space S surrounding the sleeve el in the enlargement 6 will serve as an oil reservoir so that the bearing surface between the bearing head and pocket will at all times be well lubricated.

I thus produce a very simple but highly efficient bearing for the needle bar structure in a buttonhole sewing machine. I do not desire to be limited to the exact construction and arrangement shown and described as modifications can no doubt be made which would still come within the scope of the invention.

I claim as follows:

1. In a buttonhole sewing machine, the combination of a frame, a needle bar, means for longitudinally reciprocating said needle bar, means for laterally vibrating said needle bar, a bearing sleeve receiving the upper end of said needle bar through which it reciprocates, said frame having a semi-spherical bearing pocket surrounding said needle bar, a semi-spherical bearing head on the lower end of said sleeve having bearing engagement in said bearing pocket, an adjustable abutment on said frame, and a spring interposed between said abutment and said bearing head for holding said head in bearing engagement in said bearing pocket.

2. In a buttonhole sewing machine, the combination of a frame, a needle bar, means for longitudinally reciprocating said needle bar, means for laterally vibrating said needle bar, said frame providing a bearing pocket around said needle bar near the upper end thereof, a bearing member having a bearing surface for engaging in said bearing pocket, an adjustable abutment on said frame, and a spring interposed between said abutment and said bearing member for holding it in bearing engagement in said pocket.

3. In a buttonhole sewing machine, the

combination of a frame, a needle bar, means for longitudinally reciprocating said needle bar, means for laterally vibrating said needle bar, a bearing sleeve receiving the upper end of said needle bar, a bearing enlargement on said sleeve presenting a bearing surface, said frame having a bearing pocket for receiving said bearing enlargement, an adjustable abutment on said frame, and a spring interposed between said abutment and enlargement Jfor holding it in bearing engagement in said pocket.

4. In a buttonhole sewing machine, the combination of a frame, a needle bar, means for longitudinally reciprocating said needle bar, means for vibrating said needle bar,

a bearing sleeve receiving the upper end of said needle bar through which said bar reciprocates, a bearing enlargement on said, sleeve presenting a bearing surface, said frame providing a bearing pocket for receiving said bearing enlargement, an adjustable abutment on said frame, and a spring surrounding said sleeve between said abutment and enlargement for holding said bearing surface in bearing engagement in said pocket during reciprocation and vibration of the needle bar.

5. In a buttonhole sewing machine, the combination of a frame, a needle bar disposed vertically in said frame, means for longitudinally reciprocating said needle bar, means for laterally vibrating said needle bar, means for axially rotating said needle bar, a sleeve receiving the upper end of said needle bar, a semi-spherical enlargement at the lower end of said sleeve forming a bearing head, said frame providing a semispherical bearing pocket for said head, an adjustable abutment member on said frame, and a spring surrounding said sleeve between said abutment member and bearing head for holding said bearing head in bearing relation in said bearing pocket.

6, In a buttonhole sewing machine, the combination of a frame, a needle bar vertically disposed in said frame, means for longitudinally reciprocating said needle bar, means for laterally vibrating said needle bar, means for rotating said needle bar, a bearing sleeve receiving the upper end of said needle bar in which it may reciprocate and rotate, a semi-spherical bearing head at the lower end of said sleeve, said frame providing a semi-spherical bearing pocket for said head, an adjustable abutment 0n said frame through which said sleeve eX- tends, and a spring surrounding said sleeve between said abutment and bearing head for holding said bearing head in bearing relation with said bearing pocket.

In witness whereof, I hereunto subscribe my name this lst day of March A. D., 1921.

CHARLES E. CASGRAIN. 

